Yes, the fall of 2008 was extremely optimal, did the US gov't see the problem beforehand and fix it? No they didn't, it was the market that brought the information to everyone that something was seriously amok in the financial system. (eg. Bear Stearns is bankrupt). It was short sellers, and all the people we love to hate that brought the problem to attention and moved prices to reflect the true value of these companies. (eg. zero)

Efficient market hypothesis does not predict that the market will have perfect information or perfect pricing, or that stock prices will go infinitely up. It predicts that over the long term the market provides reasonably accurate pricing.